Some young and attractive women in America have begun "mirror fasting''. They feel that glaring into mirrors obsessively is not good for them, and have given it up for up to a year. Good idea. I'm guessing "young and attractive", because I, and most of my chums, tend to avoid mirrors like the plague, except for purely practical reasons, like checking for whiskers, spinach on the teeth, where to stick your earrings and hearing aid, or in Fielding's case, when shaving.

New York beauty writer Autumn Whitefield Madrano, 36, exhausted by the pressure of continually trying to look good, tried mirror fasting for a month, and discovered that her mirror obsession had made her feel vain, and that without it she could still "be a fully functional, capable human being." Well done, Autumn, for working that out by yourself. Back in the dark ages, we were trained up not to be vain. We didn't dare be caught pouting into mirrors.

Good job, too, because now we wouldn't want to anyway. Where there used to be cheekbones and smooth skin, I see only a sagging, shapeless pancake face, with jowls, like an American president after several years in office. Why do I need to see that every five minutes? But sometimes it's unavoidable. The mirrors almost attack you. Fielding was once queueing in an American bank, looked up at the security camera and saw a bald old man. Who was it? Yes, right first time. It was him. What a ghastly shock, because he'd never seen the back of his head before, and remembered himself as a fluffy-haired, snake-hipped Rolling Stones lookalike. Not any more. Thank you, mirror.

"I don't look at my face," says Rosemary, poignantly. "There's no point in that," but in the John Lewis mirrored lift, she couldn't help but notice her whole body. She thought she'd been getting a little slimmer. The lift-mirror crushed that idea. Which is why we rarely gaze into mirrors. Abstinence gets easier as you get older. You're not depriving yourself of anything lovely. Something for Autumn to look forward to.